[PATCH 2/2] mtd: spi-nor: spansion: Add a helper for ECC related initialization

[Tudor Ambarus]

On 3/15/23 06:34, tkuw584924 at gmail.com wrote:
> From: Takahiro Kuwano <Takahiro.Kuwano at infineon.com>
> 
> JFFS2 supports write buffer mode for ECC'd NOR flash such like SEMPER
> flash family (s26hl/s25hs/s28hl/s28hs). To activate it,
> MTD_BIT_WRITEABLE needs to be unset in mtd->flags.
> 
> In existing late_init() functions for SEMPER flash family,
> params->writesize is set to 16 to avoid multiple programs in 16-byte ECC
> data unit.
> 
> This patch adds a common cypress_nor_ecc_init() helper that takes care
> for those ECC related initialization.
> 
> Signed-off-by: Takahiro Kuwano <Takahiro.Kuwano at infineon.com>
> ---
>  drivers/mtd/spi-nor/spansion.c | 33 ++++++++++++++++++++-------------
>  1 file changed, 20 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/mtd/spi-nor/spansion.c b/drivers/mtd/spi-nor/spansion.c
> index 1678b7b2e9f7..9539968c4a6d 100644
> --- a/drivers/mtd/spi-nor/spansion.c
> +++ b/drivers/mtd/spi-nor/spansion.c
> @@ -219,6 +219,22 @@ static int cypress_nor_set_page_size(struct spi_nor *nor)
>  	return 0;
>  }
>  
> +static void cypress_nor_ecc_init(struct spi_nor *nor)
> +{
> +	/*
> +	 * Programming is supported only in 16-byte ECC data unit granularity.
> +	 * Byte-programming, bit-walking, or multiple program operations to the
> +	 * same ECC data unit without an erase are not allowed.
> +	 */
> +	nor->params->writesize = 16;
> +
> +	/*
> +	 * Unset MTD_BIT_WRITEABLE to activate JFFS2 write buffer for ECC'd NOR
> +	 * flash.
> +	 */
> +	nor->mtd.flags = MTD_CAP_NORFLASH & ~MTD_BIT_WRITEABLE;

This should have been made available since the addition of the s28hx,
and it's actually a fix, thus it deserves a fixes tag and Cc to stable.

Introduce a SNOR_F_ECC, set it here and do the mtd.flags update in the
core please.

Looks good otherwise.
Cheers,
ta
> +}
> +
>  static int
>  s25fs256t_post_bfpt_fixup(struct spi_nor *nor,
>  			  const struct sfdp_parameter_header *bfpt_header,
> @@ -260,13 +276,7 @@ static void s25fs256t_post_sfdp_fixup(struct spi_nor *nor)
>  
>  static void s25fs256t_late_init(struct spi_nor *nor)
>  {
> -	/*
> -	 * Programming is supported only in 16-byte ECC data unit granularity.
> -	 * Byte-programming, bit-walking, or multiple program operations to the
> -	 * same ECC data unit without an erase are not allowed. See chapter
> -	 * 5.3.1 and 5.6 in the datasheet.
> -	 */
> -	nor->params->writesize = 16;
> +	cypress_nor_ecc_init(nor);
>  }
>  
>  static struct spi_nor_fixups s25fs256t_fixups = {
> @@ -312,13 +322,10 @@ static void s25hx_t_post_sfdp_fixup(struct spi_nor *nor)
>  
>  static void s25hx_t_late_init(struct spi_nor *nor)
>  {
> -	struct spi_nor_flash_parameter *params = nor->params;
> -
>  	/* Fast Read 4B requires mode cycles */
> -	params->reads[SNOR_CMD_READ_FAST].num_mode_clocks = 8;
> +	nor->params->reads[SNOR_CMD_READ_FAST].num_mode_clocks = 8;
>  
> -	/* The writesize should be ECC data unit size */
> -	params->writesize = 16;
> +	cypress_nor_ecc_init(nor);
>  }
>  
>  static struct spi_nor_fixups s25hx_t_fixups = {
> @@ -381,7 +388,7 @@ static int s28hx_t_post_bfpt_fixup(struct spi_nor *nor,
>  static void s28hx_t_late_init(struct spi_nor *nor)
>  {
>  	nor->params->octal_dtr_enable = cypress_nor_octal_dtr_enable;
> -	nor->params->writesize = 16;
> +	cypress_nor_ecc_init(nor);
>  }
>  
>  static const struct spi_nor_fixups s28hx_t_fixups = {